Newsio Jatamansi powder is also known as spikenard, Nardostachys jatamansi is an herb belonging to the valerian family and is found in the Himalayan region. Many Ayurvedic preparations feature jatamansi thanks to its wide-spectrum benefits. The herb is also used for cosmetic purposes, mainly to promote hair growth and to blacken hair to a deep, ebony shade. Hair benefits of Jatamansi Powder Promotes Hair Growth.Jatamansi Powder has anti-inflammatory and anti-microbial properties that prevent hair fall, dandruff and any other infectious growth in your hair. This helps promote hair growth and also it makes your hair smoother, shinier and silkier. Darkens Hair Although the cosmetic uses of the herb are well-known in Ayurveda. Jatamansi is answerable for providing the maximum darkening of hair. How to use it on Hair: You can mix Jatamansi Powder in any carrier oil that you can apply to your scalp and leave it overnight for best results. Wash your hair thoroughly with warm water in the next morning.